The most common and most likely answer to this crossword clue is the 9 letter word AVERAGING
I've seen this crossword clue in The Sunday Telegraph
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More clues leading to the result AVERAGING
- Assessing the general quality of state in decline?
- Welcome to wild evening out
- Claim in opposition to government leader, using statistical procedure
- Getting a mean hail in a storm
- Avenue out of control, more or less?
- State becoming older, losing energy and getting mean
- Doing a typical amount of damage given a rag
- Rave about old statistical procedure
- Welcome wild evening out
Buddy explains!

The straight part
We know that "using statistical procedure" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case using statistical procedure = averaging.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does AVERAGING mean?
AVERAGING verb- To compute the average of, especially the arithmetic mean.
- Over a period of time or across members of a population, to have or generate a mean value of.
- To divide among a number, according to a given proportion.
- To be, generally or on average.
- The process of computing an average.